Da Ruan Lessons Learned from Fuzzy Logic Applications in Complex Systems. 27-27 2007 EUSFLAT Conf. (1) http://www.eusflat.org/publications/proceedings/EUSFLAT_2007/papers/(A5)_Da_Ruan.pdf conf/eusflat/2007-1 db/conf/eusflat/eusflat2007-1.html#Ruan07